Retaining mechanism.



0. A. RUSS & H. B. TAYLOR. RETAINING MECHANISM.

APPucATloN FILED MAY s. 1915.

Patented Feb. 8, 1916.

vis'

`To all whom t may conce/rn:

UNITED sTATEs PATENT oEEicE.

OSCAR A. ROSS AND HERBERT B. TAYLOR, 0F ROCHESTER, NEW YORK, ASSIGNORS T0 GENERAL RAILWAY SIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OF N Ew YORK.

Application iled May 3, 1915.

Be itknown that we, OSCAR A. Ross and HERBERT B. TAYLOR, citizens of the United States, and residents of the city of Rochester, in the county of Monroe and State of New York, have invented a new and useful Retaining Mechanism, of which the'following is a specification.

This invention relates to retaining mechanism, particularly to retaining mechanism which can be used with an -electric motor and suitable control mechanism therefor to hold a movable member, such as a semaphore signal, in each of the different positions in which said member is moved by said motor.

One of the principal objects of the invention is to construct a retaining mechanism so that it may be operated by an electromagnet and may perform the additional function of a relay without losing its effectiveness as a retaining mechanism.

A further obj ect of the invention is to clonstruct an improved retaining lmechanism which facilitates the .control of a movable member, such as a semaphore signal, from a point located at a distance from said member.

Further objects and advantages of the invention will more fully appear as the description of the invention progresses, and the novel featuresof the invention will be particularly pointed out inthe appended claims.

The invention consists in a retaining mechanism operated by an electromagnet to which is also operatively connected a switch,

so that said retaining mechanism may beoperated as a relay as well as a retaining mechanism. The invention further consists in the parts, and 'in the arrangements and com binations of parts, more fully set forth hereinafter.

In describing the invention in detail, ref

y erence is had to the accompanying drawing,

wherein weA have illustrated a preferred physical embodiment of our invention, and wherein like reference characters designate corresponding parts throughout the several Views.

In the accompanying'drawing, Figure 1 is a. perspective view, diagrammatic in its nature, showing a retaining mechanism em bodying the invention, together with the preferred construction of the cooperating devices, which is used for operating a shaft Specication of Letters Patent.

RETAINING MECHANISM.

Patented Feb. 8, 1916.

Serial No. 25,595.

to different positions and for holding said shaft in each of said positions; Fig. 2 is an end view of the shaft, showing the toothed wheel which constitutes part of the retaining mechanism, and the clutch by means of which said toothed wheel is operatively connected to said shaft; and Fig. 3 is a diametrical section of the toothed wheel and its associated roller clutch, said section being taken on the line a-Z) in Fig. 2, looking in the direction of the arrow Referring to the accompanying drawing,

a retaining mechanism embodying the invention is shown as used with devices for operating a shaft 1, which may be directly or otherwise connected to a semaphore signal, or to some other movable member which it is desired to operate to a number of different positions and to control said operation from a distance. In the particular embodiment of the invention which is shown, the shaft 1 is considered to lbe weighted or otherwise biased, so as to rotate to the left, as viewed in Figs. 1 and 2. This tendency of the shaft 1 to rotate to the left may be produced in different ways; but in the drawing is shown a cord 2 wound on the shaft 1, and a weight 3 connected to said cord, whereby when said weight is raised from its lower position, in which it rests upon a suitable fixed support 4, said weight will tend to rotate said shaft. back to the left, or in a counter-clockwise direction, to its initial position. The shaft 1 is rotated in the direction opposite to the direction in which it is biased by an electric motor of suitable construction, comprising field coils 5 and an armature 6, which may be directlyy connected to the shaft 1, as shown, or by means of intermediate gearing or other mechanism.

On one end of the shaft 1 is mounted a wheel 7 having teeth 8, the faces of which` preferably extend radially of said wheel. The toothed wheel 7 is connected to the shaft 1 by a suitable clutch which permits said shaft to be rotated relatively to said toothed wheel by said motor, but which prevents rotation of said shaft relatively to said wheel in the direction in which the weight 3 tends to turn said shaft. ular construction shown, the wheel 7 is a ring on which the teeth 8 are formed, and to it are bolted two annular plates 9, one of said plates being located on each side of said wheel. Arranged between the annular plates 11'0 In the partic- 9 is an inner vclutch collar 10, which is keyed to the shaft 1, and which has in its circumferential face anumber of recesses 11, each of which is deepest at one end, this deepest end being the left hand end, as the clutch is viewed in Fig. 2. In each of the recesses 11 of the clutch collar 10 is a cylindrical roller 12 and a block 13 which block is pressed against said roller by a compression coiled spring 14 mounted in the cor-I responding recess.

The retaining mechanism is located adj acent to the'end of the shaft on which the toothed wheel is mounted; and said retaining mechanism is secured to suitable fixed frame, which may be part of the motor casing or frame or gome other fixed part associated-with the shaft. As shown, this frame comprises a base portion 15, an upright portion 16, upper cross-bar 17 and a downwardly projecting supporting member 18. PivotallyT connected to thelower end of the supporting member 18 are two swinging arms 19, which are constructed the same and are arranged flatwise in parallel planes. Between the arms 19 is mounted a sliding dog or detent 20, the nose of which is square, and has its upper and' lower faces substantially parallel. This nose of the dog 20 is guided between two freely rotatable rollers 21, mounted on pins fixed in the arms 1,9. In the opposite end of the dog 2O is a notch or slot 22 in which fits a freely rotatable roller 23, which is mounted on a pin secured to the arms 19. A flat spring 24 is pivotally connected at its lower end to the arms 19 by means of a curl or bead at its lower end which encircles a pin 25 riveted to the arms 19; and near its middle said spring engages another pin 26 riveted to the arms 19. The upper end of the spring 24 bears against the dog 20 and holds said dognor mally4 in its forward or projected pos1t1on in the path of movement of teeth 8 of the wheel 7.

The electromagnet A- which operates the arms 19 is supported by suitable means (not shown) connected to the fixed frame and has an armature 27 arranged below the arms 19. The armature 27 is pivotally mounted at one end on a pin 28 which is fixed in two upstanding lugs integral with the base portion 15. The axis on which the armature 27 is pivotally mounted is substantially vertically below the pivotal axis of the arms 19. Integral with the armature 27 and extending upwardly therefrom near its pivotal axis is an arm 30, which carries at its upper end oppositely extending studs or pins 31; and in the lower ends of the arms 19 are slots 32, in which the pins 31 of the arm 30 fit. A flat spring 33 is secured to the armature 27 and is arranged below said armature `so as to strike the base portion 15 when the armature drops, thereby cushioning the drop of said armature. A stop pin 34 is fixed to the armature 27 and extends outwardly therefrom in position to engage the base portion 15 when said armature reaches its predetermined lower position. To the armature 27 is secured an armaturebar 35 of soft iron which coperates with the pole pieces or cores ofthe electromagnet A so that when said electromagnet is ener gized the armature 27 will be raised. This electromagnet A preferably comprises two separate coils 36 and 37. The coil 36 consists of a comparatively small number of turns of large wire and is consequently of comparatively low resistance; and the other coil 37 consists-of a comparatively large number of turns of fine wire and is consequently of comparatively high resistance.

Pivotally-secred at its upper end to the cross bar 17 is a rocking switch 38, and in the lower end of said switch is a slot 39. Secured to the armature 27 is an angle member 40, and secured to the upper end of said angle member but insulated therefrom is an angle piece 41, carrying a pin 42, which fits in the slot 39 of the switch 38. By reason of this construction the switch 38 is rocked back and forth as the armature 27 moves upwardly and downwardly. The switch 38 has two oppositely projecting arms, 43 and 44. The arm 43 of the switch 3,8 is provided with a contact block 45`of carbon or similar material; and the other arm 44 has a contact piece 46, preferably of German silver, or similar material, which contact piece is wedge-shaped so as to have a sharp edge. Fixed to`a block of insulating material on the cross-bar 17 is a contact spring 47 which is arranged so as to be pressed by the carbon contact block 45; and also fixed to said insulated block and arranged to be engaged by the contact piece 46 is another contact spring 48;

The shaft 1 operates a suitable circuit controller of any suitable construction. For the purpose of showing the electrical circuits interconnecting the different parts, and to aid in the explanation of the operation of the invention, there are shown in the drawing three brushes 49, 50 and 51, which are, fixed to the shaft 1, but are insulated therefrom and fromeach other. Coperating with the brush 49 are two arcuate contact strips 52 and 53 with which the brush 49 forms electrical contact for a certain portion of the revolution of the shaft 1. The parts are shown in the initial position of the shaft 1, corresponding to the position in which the weight 3 is at its lowest point and resting upon the support 4; and for convenience in description, this initial position of the shaft 1 will be hereinafter referred to as the zero degree position. This zero degree position would correspond to the danger or horizontal position of the semaphore signal commonly used on railroads, in case this invention were applied to a semaphore signal. It is to be understood, however, -that this designation of degreesof one revolution of the shaft 1 is merely arbitrarily chosen for convenience in description, and the retaining mecha nism and its associated parts herein described are not necessarily limited to eX- actly these angular movements. The brush 49 makes contact with the strip 52from O degrees to 42 degrees, and with the strip 53 from 47 degrees to 87 degrees, said degrees representing degrees in one complete revolution of the shaft 1. The brush 50 coperates with an arcuate contact strip 54 with which it makes electrical contact from 0 degrees to 47 degrees. The brush 51 cooperates with two arcuate contact strips 55 and 56, and makes electrical contact with the strip 55 from '0 degrees to 43 degrees and with thestrip 56 from 40 degrees to 88 degrees.

The other operating parts associated with the retaining mechanism are a local source of electric current, such as a battery 57; a neutral relay 58 having two armatures, 59 and 60, which coperate with two front contacts, 61 and 62 respectively; a distant source of electric current, such as a battery 63; and two switches, 64 and 65, which are operated at a distance either manually -or by other means, such as another signal, a lever of an interlocking machine, or the like. The wires which connect the. different operating parts of the devices hereinbefore described will not be described in detail, since the electrical connections of the different parts will appear during the following description of the operation.

The mechanism hereinbefore described is designed to turn the shaft 1 from its initial position of 0 degrees, as shown in Fig; 1, to either the 45 degree' position or to the 90 degree position, and also to hold said shaft in either one of these 45 degree and 90 degree positions. With this general scheme of operation in mind, the following description of the operation can be easily understood.

Operation of moving theshaft from 0 de- `grecs to L5 degrees-This movement of the shaft is produced by closing the switch 65 at the distant point thereby supplying current from the distant source 63 to the low resistance coil 36 of the electromagnet A according to the following circuit: Positive of the source 63, conductors 66 and 67, through the closed switch 65, conductors 68` and 69, brush 50, contact strip 54, conductors 70 and 71, contact strip 52, brush 49, conductors 72 and 73, the low resistance coil 36 'of the electromagnet A, conductors 74 and 75 back to the source 63. The high resistance coil 37 of the electromagnet A is shunted or short-circuited by the following circuit: Commencing at the brush 49, through conductors 72 and 76, the high resistance coil 37, conductors 77, 78, 79 and 71, and

contact strip 52, back to the brush 49. The low resistancecoil 36 of the electromagnet A, being energized, attracts the armature bar 35 and lifts the armature 27. The upward movement of the armature 27 produces two results,-first, the arms 19 are swung toward the toothed wheel 7 to bring the nose of the dog 20 into engagement with the teeth 8 of said toothed wheel 7, and, second, the angle member 40 is simultaneously rocked and bymeans of the pin and slot connection with the switch 38 causes said switch to swing to the right in Fig. 1, thereby press'- ing the contact block 45 against thespring 47. By bringing the contact block 45 into electrical Contact with the spring 47 the operating circuit for the motor is completed as follows: Positive of the local source of cur,- rent 57 along conductors 8O and 81, contact strip 55, brush 51, conductor 82, contact spring 47, contact block 45, switch arm 38, conductor 83, through the fields 5 and the armature 6 of the motor, and along conductors 84 and 85 back to the source 57. The motor turns the shaft 1 in the right hand or clockwise direction and winds up the cord 2, thereby lifting the weight 3. During this movement of the shaft 1 the dog 20 holds the toothed Wheel 7 from turning but the direction of rotation of the shaft 1 being clockwise, the inner clutch ring 10 turns freely relatively to the toothed wheel 7.

After the shaft 1 has rotated 42 degrees, the brush 49 moves out of contact with the contact strip 52, thereby breaking the circuit hereinbefore described which shunts or short-circuits the high resistance coil 37, so that the low resistance coil 36 and the high resistance coil 37 are connectedin series to the distant source of current 63 by the following circuit: From the positive of the distant source 63, conductors 66 and 67,

through theclosed switch 65, conductors 68 and 69, brush 50, contact strip 54, conductors 70, 79, 78 and 77, high resistance coil 37, conductors 76, and 73, low resistance coil 36,

conductors 74, and 75 back to the source 63.

Since the high resistance coil and the low resistance lcoil 36 of the clectromagnet A are connected in series, the current through these coils is small; but since the armature 27 has l been previously raised, the attraction ofthe electromagneii A produced by this'small current is sufficient to holdsaid armature 1n its raised position. After the shaft 1 has turned 43 degrees' the brush 51 moves out of contact with the contact strip 55, and breaks the operating circuit for the motor hereinbefore described. The power of the motor being cut off, the shaft 1, after vrotating through a small angle beyond 43 degrees,

v position.

current through the snubbing resistance 94 and this generating action of the motor causes the armature thereof to be retarded or snubbed. By reason of this snubbing action the weight is gently returned to its initial position. During this return rotation of the shaft l all other circuits hereinbefore described are opened.

The operation of returning the shaft from .90 degrees to i5 degrcee.-This movement of the shaft is accomplished by opening the switch 64 which denergizes the relay 58 and causes its armatures 59 and 60 to drop. The dropping of the armature 60 opens the series circuit hereinbefore described through the high resistance coil 37 and the low resistance coil 36 of the electromagnet A. The electromagnet A being denergized, the armature 27 thereof dropsby its own weight, and, .as hereinbefore described, releases the shaft 1 and permits the weight 3 to rotate said shaft in the counter-clockwise or reverse direction. The shaft 1 is rotatedI by the weight 3 until it reaches the 47 degree A-t this 47 degree position the series circuit through the coils of the electromagnet A hereinbefore described is established, but due to the small amount of current iiowing through the coils of said electromagnet A' and the comparatively high drop of its armature 27, the attraction of said 'electromagnet is not suiicient to lift its armature. At 43 degrees the break of the motor circuit at the circuit controller is closed, since the brush 51 makes Contact with the contact strip 55; but since said motor operating circuit is interrupted at the carbon contact block 45, no current is supplied to the motor. At 42 degrees the brush 49 makes contact withthe contact strip 52, thereby completing the circuit through the low resistance coil 36 of the electromagnet A from the distant source 63, as hereinbefore described, thev high resistance coil being simultaneously shunted or short-circuited. When current flows through the low resistance coil 36 alonethe attraction of the electromagnet A is made large enough to lift itsarmature 27. The lifting ofthe magnet 27 moves the switch 38l and breaks-the snubbing circuit and completes the motor operating circuit; and also moves the dog 20 into the path of the teeth 8 of the wheel 7. The operating circuit for the motor being completed the motor starts the shaft in a clockwise direction to re-wind the weight, and this movement of the shaft takes place for about one degree (from 42 degrees to 43 degrees), whereupon the motor circuit is again interrupted by the brush 51 moving out of contact Vwith the contact strip 55. The shaft 1 continues its rotation after current to the motor has been cut olf for a short distance, due to its acquired momentum, then stops, and then under vthe iniiuence of the Weight 3 rotates in reverse direction for a short distance until the clutch between the shaft l and the toothed wheel 7 grips and holds said shaft in its 45 degree position. The shaft 1 is returned from its 45 degree position -to its zero degree position by opening the switch 65, which interrupts the supply of current to the electromagnet A from the distant source 63.` The shaft 1 is returned by the weight 3 to its initial or zero degree position, the snubbing circuit being closed as hereinbefore described, and the motor operating circuit and all of thecircuits through the electromagnet A being open.

From the foregoing description it can be seen that the shaft 1 is operated in accordance with the movements of the switches 64 and 65 from its normal position to any one of two positions, being held in each one of these positions by the engagement of the dog 20 with 7. The armature 27 of the electromagnet A not only actuates the dog 20, which coperates withthe wheel 7 and the clutch between said wheel and the shaft 1 to hold said shaft in its different operated positions, but also operates the switch 38, so as to perform the function of a relay. y

It is preferable, for the reasons of safety, to construct and arrange the parts of a retaining mechanism so that the releasing thereof is not dependent' upon any tendency of the shaft'l to return to its original osition. In other words, the armature 2 of the electromagnet A should be heavy enough that it will drop and release the toothed wheel 7 when current ceases to flow through one of the teeth 8 of the wheel 1 the coils of said electromagnetand will do so without the assistance of any other` force.

When the weight of the armature 27 alone is relied upon to release the retaining mechathe dropping movement of the armature 27,

since said spring is under tension when said armature is raised.

l The dog 20 might be Xed to or integral with the arms 19, except for the fact that the shaft 1 might return to its zero degree position with one of the teeth 8 of the Wheel 7 positioned directly opposite the dog 20. Under such conditions the movement of the arms 19 and also of the armature 27 and the switch 38, would be prevented. In the construction shown and described, however, the

izo

the parts shown and hereinbefore described,l

the shaft 1 is operated to either one of two different positions by a motor supplied with current from a local source and the movements of said shaft are [controlled from av distant point by the use of only one relay 58 and the coils of the electromagnet A which operates the retaining mechanism.

During the normal operation, as hereinbefore described, the motor o-perating circuit is brokenby the movement of the brush 5l out of contact with either the contact 'strip 55 or the contact strip`56, as the case may be, and since said brush is mo-ved by the motor, there is sufficient force to separate said brush from either' of said contact strips in case said brush should be fused to either of said contact strips by the arc produced in breaking the motor operating circuit. Under some circumstances, however, the motor operating circuit may be bro-ken by the separation of the carbon contact vblock 45 and the contact spring 47; as for instance, when either of the controlling switches 64, 65v is opened after once being closed and before the corresponding movement of the shaft has been finished; and under sulch circumstances, a dangerous condition might be produced if these coperating contacts of the motor operating circuit were to be fused. A dangerous condition would result because the weight of the armature 27 is not sufficient to pull fused contacts apart; and if the armature does not drop, the retaining mechanism is not released, so that the shaft will be held in its raised position regardless of the positions of the controlling switches 64 and 65. By making the contact 45 of carbon, or similar material, which will not'fuse with metal, the possibility of 'this above-mentioned dangerous condition is obviated.

Although we have particularly described the construction of one physical Iembodiment of our invention, and explained the operation and principle thereof; nevertheless, we desire to have it understood that the form selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of means underlying our,

invention.

What weclaim as new and'desire to secure by Letters Patent of the United States,

1. The combination of a rotatable shaft biased to rotate in onedirection, of an electric motor for rotating said shaft in the opposite direction, a toothed wheel loosely mounted on said shaft, a detent movable into and out .of engagement with'the teeth of said wheel, a clutch between said shaft and said. wheel which permits said shaft to be rotated by said motor relatively to 'said wheel but which prevents said relative rotation of said shaft in the opposite direction, an operating circuit for; said motor, and means for closing said motor operating circuit and for Simultaneously moving said detent into engagement with said toothedy wheel.

2. lA combinationwith, a rotatable shaft biased to rotate in one. direction, of an electric motor for rotating said shaft in the opposite direction, a toothed wheel mounted on said shaft, a clutch between said' wheel Jand said shaft which permits said shaft to be rotated by said motor relatively to said wheel but which prevents said relative rotation of said shaft in the opposite direction, a detent movable into engagement with said wheel, and electromagnetic means for operating said detent.

3. In a retaining mechanism, in combination: a rotatable shaft biased to rotate in one direction; a motor for rotating said -shaft in the opposite direction; a toothed wheel loosely mounted on said shaft; a lclutch mechanism interposed between said shaft and said wheel and permitting said shaft to be rotated by said motor relatively to said Wheel, but preventing such relative rotation in the opposite direction; ai detent movable into and out of Vengagement with the teeth of said wheel; an operating circuit for said motor; a circuit controller included in said circuit and connected to said detent and operated simultaneously therewith; means for operating said detent and said circuitcontroller; and yielding means for permitting said circuit controller to be operated by said means independently of said detent. v

4, A combination with a rotatable shaft biased to rotate in one direction, of an electric motor for rotating said shaft in the opposite direction, a detent for holding said l rection from a normal or initial position to a second position and for holding said shaft in said second position against rotation in they direction in. which it is biased, said means comprising an electric motor for rotating said shaft in said opposite direction,

a local source of electric current, a localv said motor relatively to said wheel but which prevents such relative rotation in the opposite direction, a detent movable into and out of engagement with the teeth of saidrwheel for holding said shaft against rotation in the' direction in which it is biased, an 'electromagnetic device for operating said local switch and said detent, said elec` tromagnet when energized closing said 'local switch and actuating said detent to hold said shaft, and meanscontrolled from a distance for energizing said electromagnet, v

6. A combination with a rotatable shaft biased to rotate in one direction, of means for rotating said shaft in the opposite direction Jfrom a normal or initial position to either a second or a thirdv position, and for holding said shaft in said second and third positions against rotation in the direction in which it is biased, said means comprising an electric motor for rotating said shaft in saidxopposite direction, a local source of electric current, a local switch, a circuit including said local source, said motor and said local switch, a circuit controller -ineluded in said circuit and operated by said shaft to close said circuit during the rotation of said shaft from said Afirst position to said second position and to open said circuit nwhen said shaft attains said second position, a detent for holding said shaft against'rotation in the directionf in which it is biased', an electromagnetic device .for operating said local switch and said detent, said electromagnet when energized closing said local switch andactuating saidI detent to hold said shaft, a distant soureefof electric current, a distant switch, a second 'circuit including said distant source, said distant switch and said electromagnet, a second circuit controller included in said second circuit and operatedi by said shaft to close said second circuit during the rotation of said shaft from said first position to said second position and to open said circuit when said shaft attains said second position, .a relay having two front contacts, a third circuit controller operated by said shaft to close said first circuit through one of said relay contacts during the rotation of said shaft from said second position to said third position, said other relay contact closing said second circuit during the rotation of said shaft from its second to its thirdposition, and means for controlling said relay from a distance.

7. The combination with a rotatable shaft biased t'o rotate in one direction, of an electric motor for rotating said shaft in the opposite direction, a toothed wheel mounted on said shaft, a clutch between said wheel and so said shaft which permits said shaft to be rotated by said motor yrelatively to said wheel but which prevents said relative rotation of said shaft in the opposite direction,

a swinging arm carrying a dog adapted to engage one of the teeth of said wheel, an operating circuit for said motor, a switch included in said operating circuit, and an electromagnet having a gravitating armature, said armature being operatively connected to said swinging arm and to said switch.

8. A combination with a rotatable shaft` biased to rotate in one direction, of an electric motor for rotating said shaft lin the opposite direction, a toothed wheel loosely mounted on said shaft, the'teeth ofA said wheel having radial faces, a detent movable into and out of engagement with the teeth of said wheel and having faces'extending 100 substantially radially of said wheel, a clutch between said shaft and said wheel which permits said shaft. to be rotated by said motor relatively to said wheel but which prevents said relative rotation of said shaft in the opposite direction, and electromagnetic means .for moving said detent into en-y gagement with said wheel..

9. A combination with a rotatable shaft biased to rotate in one direction, of an electric motor for rotating said shaft in the" opposite direction, a toothed wheel loosely mounted on'said shaft, a swinging arm carrying a dog adapted to engage one of the teeth of said wheel, a clutch between said wheel fand said. shaftwhich permits said shaft to be rotated by said motor relatively to said wheel but which prevents such relativel rotation of said shaft in the opposite direction, an' operating circuit for said 120 motor, electromagnetic means for swinging said arm to bring saidI dog into engagement with the teeth4 of said wheel, and means operated at a predetermined time with reference to the operation of said electromag- 1 25 netic mea-ns for opening and closing said motor circuit.

10. rlhe combination with a rotatable shaft biased to rot-ate in one direction, of

'an electric motor for rotating said shaft in 130 the opposite direction, a toothed wheel operatively connected to said shaft, a detent movable into engagement with the teeth of said wheel, a local source of electric current, a circuit controller operated by said shaft and having` a pair of coperating contacts held closed for predetermined amount of lmovement of said shaft, an operating circuit for said motor' including said4 local source, said circuit controller and saidv motor, a snubbing circuit for said motor 1ncludiiig resistance, a switch having coperating contacts arranged to close said niotor operating circuit and said snubbing circuit alternately, an electromagnet having al gravitating armature, said switch and said detent being operatively connected to said armature so that said .Switch closes said inotor operating circuit when said detent engages the teeth of said wheel, and means for energizing said electromagnet Afrom a distance.

1l. A combination with a rotatable shaft biased to rotate in one direction, of an elec* circuit for said electromagnet controlled at a distance, a circuit controller included in said circuit and operatively connected to said shaft, said circuit controller having cooperating contacts which are closed for a predetermined part of movement of said shaft, an operating circuit for said motor which includes said switch, a second-circuit controller ,included in said motor operating circuit and operatively connected to said closed for a predetermined part of the movement of said shaft less than the aforesaid predetermined part of movement of said shaft, and a snubbing circuit for said motor, said snubbng circuit being closed by said switch in the position thereof in which said detentvdoes not hold said shaft.

12. .A combination with a rotatable shaft biased to rotate in one direction, a motor for rotating said shaft in the opposite direction, a detent for holding said shaft against movement in the direction of biased rotation, a switch having two arms, one of said arms having a' carbon contact and the other of said arms having a sharp edge, a metallic contact adapted to be pressed by said carbon contact, a second metallic contact arranged at an acute langle to the direction of movement of the sharp edge of said other arm, whereby said sharp -edge of said other arm slides over the surface of said second metallic con'tact in making contact therewith, and electromagnetic means for actuating said switch and for moving said detent to its holding position simultaneously.

13. In combination with a rotatable shaft biased to rotate in one direction, a motor for rotating said shaft in the opposite direction, a clutch collar fastened to said shaft and having recesses in its periphery which are deeper at one end, a clutch ring surrounding-said clutch collar and having teeth -on its outer periphery, rollers disposed in said recesses of said clutch collar, annular plates secured to said clutch ring and 'overlying the ends of said rollers, and a detent for cooperating with the teeth of said clutch ring.

i OSCAR A. ROSS.

HERBERTB. TAYLOR. 

